chemistry 3102a thermodynamics & rates · chemistry 3102a thermodynamics & rates curriculum...

Adult Basic Education

Science

Chemistry 3102A

Thermodynamics & Rates

Curriculum Guide

Prerequisite: Chemistry 2102C

Credit Value: 1

Chemistry Concentration

Chemistry 1102 Chemistry 2102AChemistry 2102BChemistry 2102CChemistry 3102AChemistry 3102BChemistry 3102C

Table of Contents

To the Instructor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vIntroduction to Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vCurriculum Guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vStudy Guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viResources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viRecommended Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Unit 1 - Temperature Change and Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2

Unit 2 - Enthalpy Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6

Unit 3 - Calorimetry and Hess’s Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12

Unit 4 - Collision Theory, Reaction Mechanisms, and Catalysts . . . . . . . . . . . . . . . . . . . Page 16

Curriculum Guide Chemistry 3102Av

To the Instructor

I. Introduction to Course

Chemistry 3102A introduces students to the ways that energy changes are involved inphysical and chemical changes. This information is then further developed in a study ofthe factors affecting reaction rates and an examination of what is happening at amolecular level.

Students taking this course need to know how to solve for unknowns and use a scientificcalculator. Instructors should ensure that students have these prerequisite skills. Chemistry 3102A, along with Chemistry 3102B and C, are equivalent to Chemistry 3202

in the current high school program. Chemistry 2102C is a prerequisite to this course.

II. Curriculum Guides

Each new ABE Science course has a Curriculum Guide for the instructor and a StudyGuide for the student. The Curriculum Guide includes the specific curriculum outcomesfor the course. Suggestions for teaching, learning, and assessment are provided to supportstudent achievement of the outcomes. Each course is divided into units. Each unitcomprises a two-page layout of four columns as illustrated in the figure below. In somecases the four-column spread continues to the next two-page layout.

Curriculum Guide Organization:The Two-Page, Four-Column Spread

Unit Number - Unit Title Unit Number - Unit Title

Outcomes

Specific

curriculum

outcomes for

the unit.

Notes for Teaching and

Learning

Suggested activities,

elaboration of outcomes, and

background information.

Suggestions for Assessment

Suggestions for assessing

students’ achievement of

outcomes.

Resources

Authorized and

recommended

resources that

address

outcomes.

Curriculum Guide Chemistry 3102Avi

To the Instructor

III. Study Guides

The Study Guide provides the student with the name of the text(s) required for the courseand specifies the sections and pages that the student will need to refer to in order tocomplete the required work for the course. It guides the student through the course byassigning relevant reading and providing questions and/or assigning questions from thetext or some other resource. Sometimes it also provides important points for students tonote. (See the To the Student section of the Study Guide for a more detailed explanationof the use of the Study Guides.) The Study Guides are designed to give students somedegree of independence in their work. Instructors should note, however, that there ismuch material in the Curriculum Guides in the Notes for Teaching and Learning andSuggestions for Assessment columns that is not included in the Study Guide andinstructors will need to review this information and decide how to include it.

IV. Resources

Essential Resources

Chemistry: Mustoe, Jansen, et al; McGraw-Hill Ryerson, 2004.McGraw-Hill Chemistry Teacher’s Resource (including CD-ROM)

Recommended Resources

Chemistry 3202 Curriculum Guide:http://www.ed.gov.nl.ca/edu/sp/chem_3202.htm

Chemistry 11/12 Computerized Assessment Banks.Textbook website:http://www.mcgrawhill.ca/school/booksites/chemistry/index.php

Other Resources

Center for Distance Learning and Innovation: http://www.cdli.ca/

Access Excellence Resource Center:http://www.accessexcellence.org/RC/chemistry.html

Virtual Chemistry: http://neon.chem.ox.ac.uk/vrchemistry/

http://www.mcgrawhill.ca/school/booksites/chemistry/index.php

http://(http://www.cdli.ca/)

http://www.accessexcellence.org/RC/chemistry.html

http://neon.chem.ox.ac.uk/vrchemistry/

Curriculum Guide Chemistry 3102Avii

To the Instructor

V. Recommended Evaluation

Written Notes 10%Labs/Assignments 20%Test(s) 20%Final Exam (entire course) 50%

100%

The overall pass mark for the course is 50%.

Thermodynamics & Rates

Unit 1 - Temperature Change and Heat

Curriculum Guide Chemistry 3102APage 2

Outcomes Notes for Teaching and Learning

1.1 Explain temperature and heatusing the concept of kinetic energyand the particle model of matter.

1.1.1 Definethermochemistry.

1.1.2 Distinguish betweensystem and surroundings.

1.1.3 State the First Law ofThermodynamics.

1.1.3 Define open, closed,and isolated systems.

1.1.4 Define temperature asa measure of the averagekinetic energy of theparticles of the system.

1.1.5 Identify and describethe changes to particlemovement in systems inwhich the energy change isaccompanied by a change intemperature of the system.

1.1.6 Describe heat as atransfer of kinetic energyfrom a system of highertemperature (higher averagekinetic energy) to a systemof lower temperature (loweraverage kinetic energy)when each is in thermalcontact with the other.

Instructors should make sure that students review theterms energy, kinetic energy and potential energy.

After defining temperature the instructor could usetemperature differences in the classroom to illustratedifferences in particle movement and heat. Forexample, ask students to place a hand on their desk. The desk will feel cool. What's happening? Thetemperature of the hand is higher than the temperature

Kof the desk, therefore the kinetic energy (E or KE)

K(particle movement) in the hand is higher than the E(particle movement) in the desk. The result is a transfer

Kof E from the particles in the hand to particles in thedesk as collisions occur in the interface. This is heattransfer from the hand to the desk.

Students may still confuse heat and temperature.Instructors should make sure they understand thattemperature is a measure of the average thermal energyof a substance, while heat describes the transfer ofthermal energy.

Whenever a temperature change occurs, the change in

KE involved can be determined from experimentallyobtained data or from data provided, using the First Lawof Thermodynamics.



Suggestions for Assessment Resources

Students could be asked to distinguish between temperature andheat by relating these to the energy of the atoms and molecules.

Students could respond to the following questions:

Explain why, on a hot, summer day at the beach, the sand can beunbearably hot on bare feet yet the water is very cold.

What happens when direct sunlight is blocked by a cloud? Howdoes this affect the temperature of the sand versus that of thewater ?

Why is it helpful to fill your thermos bottle with hot water beforefilling it with a hot beverage?

Students could be told they can use a balance to find the mass ofa substance only when it is at room temperature. They shouldexplain this statement.

They should be able to give an example of an experiment to showthat two objects at the same temperature do not necessarily havethe same thermal energy.

The CDLI (Center for Distance Learning and Innovation) websitewas developed for distance delivery of selected high schoolcourses. It contains lots of materials that could be useful in thedelivery of ABE courses.

Note: You will need a username and password to enter the CDLIsite.

MGH Chemistry, pages 624 - 638.

Teacher’s Resource forMGH Chemistry pages236-259 (including CD-ROM).

Website for the text:http://www.mcgrawhill.ca/school/booksites/chemistry/index.php

Department of Educationwebsite:http://www.ed.gov.nl.ca/edu/science_ref/chem3202.htm

The centre for distancelearning and innovationwebsite: http://www.cdli.ca/




http://www.ed.gov.nl.ca/edu/science_ref/chem3202.htm



http://www.cdli.ca/




1.2 Calculate and compare theenergy involved in changes oftemperature.

1.2.1 Define the terms:joule, heat capacity andspecific heat capacity.

1.2.2 Identify that theamount of heat lost orgained by an object isdependent upon; type ofmaterial, change intemperature of material, andmass of material.

1.2.3 Perform calculationsinvolving heat capacity, C,and specific heat capacity,c.

1.2.4 Calculate the heatgained or lost from a systemusing the formulas q =mcÄT or q = CÄT where c is thespecific heat capacity, C isthe heat capacity and ÄT isthe change in temperature.

Students can achieve outcome 1.1.6 by completingThoughtLab - Factors in Heat Transfer.

Students need to understand that the change intemperature depends on the type of material and themass, which should be illustrated through the conceptsof heat capacity (C) and specific heat (c). For example,you wish to boil water for a cup of tea. Why would it befaster to place 250 mL of water in the kettle rather than2000 mL of water? This reinforces the concept of theimportance of mass to energy lost or gained.

It requires more energy to raise the temperature of a 1kg aluminium frying pan by 200 C than it does to raiseo

the temperature of a 1 kg iron frying pan 200 C. Why? o

This reinforces the concept of the importance of the typeof matter to energy lost or gained. This leads into theexplanation of specific heat and related calculations.

A 20.0 g piece of iron has a heat capacity of 8.88 J/ C. o

Calculate the specific heat of iron. The specific heat ofaluminium is 0.890 J/g C. Calculate the heat capacityo

of a 500 g aluminium saucepan. Refer to the table ofspecific heat values for comparison. The previouscalculation can quickly lead to calculation of heat lost orgained using the formula q = mCÄT .

Practise using this formula for calculating one of q, m,c, or ÄT given the other three variables. Instructorsshould note that math skills in rearranging formulas maybe weak for some students. For example, how much energy is lost when analuminium mailbox, with a mass of 400.0 g, cools from26.2 C to 12.4 C ?o o




Instructors should use question 1.10 of the Study Guide,Completion of the Though Lab, for assessment of outcome 1.2.2.Answers to Procedure questions and Analysis question can befound in the Teacher’s Resource.

Instructors could use Practice Problems, Section Review and UnitReview questions to assess students’ understanding of theconcepts covered in Unit 1.

Students may check the answers to the Practice Problems in thetext by referring to page 659. Instructors should make sure thatstudents are using the correct procedures to arrive at theseanswers.

Instructors should check students’ answers to all questionsassigned in the Study Guide for this unit.

ThoughtLab - Factors inHeat Transfer, MGHChemistry page 631.

The centre for distancelearning and innovationwebsite: http://www.cdli.ca/Chemistry 3202: Unit 03:Section 02

http://www.cdli.ca/

Unit 2 - Enthalpy Changes



2.1 Understand enthalpy changesfor physical and chemical changes.

2.1.1 Define the terms:enthalpy, molar enthalpychange (ÄH), exothermicreaction and endothermicreaction.

2.1.2 Use and interpretchange in enthalpy (ÄH)notation for communicatingenergy changes.

2.1.3 Identify and explainthat chemical changes andphase changes involvechanges in potential energyonly.

Students should write thermochemical equations torepresent enthalpy notation.

The sign of ÄH is negative for exothermic processes(energy is a product in the reaction) and positive forendothermic processes (energy is a reactant in thereaction).




Ask students to explain what is happening in terms of potentialenergy for physical and chemical changes when (a) heat is lost bya process or (b) heat is gained by a process. Similarly ask themwhat is happening if the process is exothermic or endothermic.

The Chemistry Teacher’s Resource has some good suggestions(see pages 241-242) to demonstrate the concepts introduced inthis unit.

MGH Chemistry pages:639-640.




2.2 Illustrate changes in energy ofvarious chemical reactions, usingpotential energy diagrams.

2.2.1 Draw and interpretpotential energy diagramsbased on experimental datafor chemical changes.

2.2.2 Label enthalpydiagrams given either the ÄH for a process, or athermochemical equation.

2.2.3 Identify exothermicand endothermic processesfrom the sign of ÄH, fromthermochemical equations,or from labelled enthalpydiagrams.

2.2.4 Writethermochemical equations,including the quantity ofenergy exchanged, giveneither the value of ÄH or alabelled enthalpy diagram.

Emphasize understanding of Figures 16.11 and 16.12 oftext as these are fundamental to understandingactivation energy diagrams in Unit 4.

Instructors could ask students for everyday examplesinvolving endothermic and exothermic changes. Examples might include heating and freezing of ice, hotand cold packs, evaporation and condensation of water,and production and decomposition of ammonia.




Use the data in Table 16.2 and ask students to represent theinformation as (a) thermochemical equations (b) separateexpressions or (c) enthalpy diagram. Problem 2 on page 657 oftext covers these representations.

MGH chemistry pages641-643.




2.3 Calculate and compare theenergy involved in changes of stateand in chemical reactions.

2.3.1 Use the formula q =n@ÄH to calculate the heatabsorbed or released by aprocess.

2.3.2 Explain that energy isrequired by a systemwhenever attractive forcesbetween particles arebroken and that energy isreleased from a systemwhenever new attractiveforces form betweenparticles (bond-breaking vs.bond-forming)

2.3.3 Identify and explainthat energy changes areobserved during phasechanges and chemicalchanges where forces ofattractions between particlesare formed or broken yet nochange in the temperatureof the system occurs.

2.3.4 Calculate heatchanges for changes ofstate.

2.3.5 Calculate heatchanges when a substancechanges temperature.

2.3.6 Calculate total heatabsorbed or released by asystem.

It is very important for students to understand thatduring chemical and phase changes there is no change intemperature of the system although temperature changesmay be observed in the surroundings.

For example, a candle burns and releases energy equalto the change in potential energy between the reactants

2(candle wax and oxygen) and the products (CO and

2H O). This energy is observed as it warms up thesurrounding air and unburned candle wax (melted wax). This concept is more easily understood in phase changesbecause, for example, everyone is familiar with purewater freezing at 0 C, and at 0 C only (at 1 atm).o o

It is often valuable to get students to heat a beaker of iceand measure the temperature during the process.Students are often astonished that as long as there is icepresent, there is no change in temperature. Similarly aslong as the liquid is boiling the temperature stops rising.

Break energy changes for systems e.g. ice at -35 Co

steam at 110 C into its various separate steps for theo

students. Ask them to identify how they would calculatethe heat required for each step.




Instructors should check student answers to all study guidequestions.

Additional questions such as the following can be used:

How much heat is released as 150 g of steam at 125 C is cooledo

to water at 25 C?o

How much heat is required to convert 15 g of ice at -40 C too

water at 6.5 C?o

Instructors could also select questions from the Section Review,Chapter Review, or Unit Review to assign for assessment ofstudents’ understanding of the concepts covered in this unit. Fullsolutions for all problems in the text are provided on theTeacher’s Resource CD-ROM. The CD-ROM also provideschapter tests with solutions. Instructors could select questionsfrom the chapter tests and/or the computerized assessment bankfor use as assessment and/or evaluation tools.

MGH Chemistry: pages643-647; 653-655.

MGH Chemistry,Teacher’s Resource CD-ROM.

MGM Chemistry 11/12,ComputerizedAssessment Bank CD-ROM.

Unit 3 - Calorimetry and Hess’s Law



3.1 Understand how to measureheat changes

3.1.1 Identify the basicinstrument for measuringheat transfer and theassumptions made in heattransfer experiments.

3.1.2 Apply the equation

system surroundings q = -q to determine heat transfer.

3.1.3 Calculate heatchanges for simpleprocesses.

3.1.4 Measure the enthalpyof neutralization for thereaction of hydrochloricacid and sodium hydroxide.

Students commonly forget to change the sign for heat. Ifthe temperature of the system rises in a coffee cup theygenerally think of this as the reaction beingendothermic.

Remind them that the contents of the coffee cup isincreasing in temperature because the system isreleasing heat to the surroundings. The reverse happensfor an endothermic process. The system absorbs heatfrom the surroundings and the measured temperaturedrops.

Investigation 17-A is easy to perform. If HCl is notavailable, acetic acid (vinegar) could be used. If NaOH

3is not available, solid baking soda (NaHCO ) canweighed and used. You may have to experiment withquantities to determine what gives a reasonabletemperature change.

Consult the MGH Chemistry Teacher’s Resource forsafety precautions and tips on carrying out the lab andfor answers to all the lab questions.




Questions similar to the Sample Problem on page 663-664 can begiven using different metals.

Also, other acid -base reactions similar to that done in the lab,can be used as examples for practice. Blackline Master 17-1 canbe used here.

Students must complete and submit the Core Lab for grading. Ifthey have not submitted lab report to you before, they will needguidelines.

MGH Chemistry pages660-664.

Core Lab:Investigation 17-A,“Determining theEnthalpy of aNeutralization Reaction”,pages 668-669.

BLM 17-1, “Enthalpy ofNeutralization”.




3.2 Understand Hess’s Law ofHeat Summation.

3.2.1 State Hess’s law ofheat summation.

3.2.2 Draw enthalpydiagrams to show how theenthalpy for a reaction canbe determined from severalseparate enthalpy changes.

3.2.3 Determine theenthalpy change of anoverall process using themethod of addition ofchemical equations andcorresponding enthalpychanges.

Keep the problems used here to two step processes.Students frequently find that using enthalpy diagramsgives them a better understanding of Hess’s lawapplications.

If time and equipment permit, try Investigation 17-C.Completing this investigation will give students furtherexperience in calorimetry calculations as well as a two-step Hess’s law calculation. Consult the Teacher’sResource for safety precautions and tips for carrying outthe investigation.

Instructors should point out that Hess’s law is a methodof determining ÄH for reactions that are too difficult,too expensive, too slow, or too dangerous to measureexperimentally (eg. using calorimetry).

An analogy is useful here to illustrate that Hess’s Law isbased on the concept that the energy involved in achemical reaction is independent of the path taken tochange reactants into products. An example might be tosuggest the whole class meet at a a particular spot laterin the day. Each person may take a different route butthe outcome is the same.




Study Guide questions 3.9 and 3.10 cover outcome 3.2. Instructors could assign problems similar to practice problems 11and 12 on page 681 for extra practice.

Instructors should check student answers to all study guidequestions for this unit and provide extra practice if needed.

MGH Chemistry: pages677-681.

Unit 4 - Collision Theory, Reaction Mechanisms, and Catalysts



4.1 Understand the meaning of rateof a reaction and the factors thataffect reaction rate.

4.1.1 Define reaction rate.

4.1.2 Recognize thatreaction rate can bemeasured by monitoring avariety of changingmacroproperties including;mass, colour, volume andpH.

4.1.3 Identify the factorsthat affect reaction rate.

4.2 Describe collision theory andits connection to factors involved inaltering reaction rates

4.2.1 State the KineticMolecular Theory (KMT)of matter.

4.2.2 State the collisiontheory.

4.2.3 Explain usingcollision theory howtemperature,concentration/pressure,surface area and nature ofreactants affect the rate ofreaction.

4.2.4 Describe the effect ofa catalyst on the rate ofreaction.

Instructors should introduce the topic of rates ofreaction by using examples to point out to students thatreactions proceed at varying rates and sometimes do notoccur at all. They should make sure that students realizethat rate of reaction is a measurement of a change inquantity over a change in time.

Instructors could demonstrate some of themacroproperties that can be observed to measure rate ofreaction (see Resource Guide, p.187).

Explain to students that a balloon stays inflated due tothe ideas of the KMT (Kinetic Molecular Theory). According to the KMT, the gas particles are in constantmotion, moving as far apart as possible. The ideas ofthe KMT also apply to the diffusion of the scent ofperfumes through a room.

Instructors should note that there are manygeneralizations regarding the effect of nature ofreactants on reaction rate. Students should realize thatthe type of bonding within reactants and products has aprofound impact on reaction rate.

It would be useful to provide students with theopportunity to visualize reactions occurring at themolecular level. Videos and the Internet are goodsources for animations and simulations of collisions andreactions in 3-D.




Instructors will find questions that may be used for review,reinforcement and/or assessment in the Section Review, ChapterReview and Unit Review in the text. There are AdditionalPractice Problems found on the Teacher’s Resource CD-Rom.

Instructors could direct students to the text website. It containsStudy Quizzes for Chapter 12 that students could use for selfassessment.

MGH Chemistry, pages460-481.

Teacher’s Resource forMGH Chemistry(including CD-Rom).

Website for the text:http://www.mcgrawhill.ca/school/booksites/chemistry/index.php

Department of Educationwebsite:http://www.ed.gov.nl.ca/edu/science_ref/chem3202.htm

The centre for distancelearning and innovationwebsite: http://www.cdli.ca/







http://www.cdli.ca/




4.2.5 Define, draw, andlabel a potential energydiagram for exothermic andendothermic reactions(overall or one-stepmechanism). Include:(i) labelled axis(ii) activation energy(iii) activated complex site

(iv) ÎE

(v) reactants and products

Full solutions for Practice Problems are in the SolutionsManual on the Teacher’s Resource CD-Rom.




Students should draw a potential energy diagram and they shouldcorrectly label it for an endothermic and exothermic reaction.Include the shape of the curve, correct labelling for activationenergy and energies of reactants, products, and activatedcomplex.

Students can be given BLM12-2, “Potential Energy Diagrams”,for assessment of their skill level in drawing and interpretingpotential energy diagrams.

Instructors should check student answers to all questions assignedin the study guide for this unit.

Instructors should choose appropriate Section Review, ChapterReview, and Unit Review questions to be completed for review,reinforcement and assessment of how well the student hasachieved success in reaching the outcomes for the chapter.

BLM 12-3, “Chapter 12 Test” (or portions of it), can be used toassess student understanding of the concepts in Chapter 12.

A final comprehensive exam should be given for the course. Themark on the exam should comprise at least 50% of the final markfor the course.

“ Web Links” referencedon the textbook’s websiteunder Teacher Resources.

CDLI website atwww.cdli.ca/

Teacher’s Resource CD-ROM, BLM 12-2,“Potential EnergyDiagrams”. BLM 12-3,“Chapter 12 Test”.

chemistry 3102a thermodynamics & rates · chemistry 3102a thermodynamics & rates curriculum...

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